A data-* attribute on an <optgroup> tag attaches additional data to the option group element.
To create a custom attribute, replace * with a lowercase string, such as data-id, data-status, or data-location.
A custom data-price attribute on an <optgroup>.
The attribute value is not visible, but it is readable by JavaScript.
<select>
<option value="">-- Select color -- </option>
<optgroup label="One Color" data-price="+$5.00">
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
</optgroup>
<optgroup label="Two Colors" data-price="+$8.20">
<option value="red and blue">Red and Blue</option>
<option value="black and yellow">Black and Yellow</option>
<option value="blacka and red">Black and Red</option>
</optgroup>
</select>
The data-* attribute adds custom information to an <optgroup> element.
The * part is replaced with a lowercase string, such as data-id, data-cost, or data-location.
An <optgroup> element can have any number of data-* attributes, each with their own name.
Using data-* attributes reduces the need for requests to the server.
Note: The data-* attribute is not visible and does not change the appearance of the optgroup.
<optgroup data-*="value">
Note: The * can be any string, such as data-id, data-cost, data-supplier, etc.
| Value | Description |
|---|---|
| value | A string value. Can be numeric, alphanumeric, JSON, etc. |
A custom data-content attribute on an <optgroup> tag.
Clicking the button will display the content value.
<select>
<option value="">-- Select color -- </option>
<optgroup id="myoptgroup" label="Primary Colors" data-content="Colors">
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
</optgroup>
</select>
<br/>
<button onclick="show();">Show data</button>
<script>
let show = () => {
let element = document.getElementById("myoptgroup");
alert("Content = " + element.getAttribute('data-content'));
}
</script>
The <optgroup> tag has a custom data-content attribute.
The data-content attribute stores the content of the option group.
Clicks are handled by the onclick event.
Onclick invokes a JavaScript function that extracts and displays the <optgroup> content.
Note: Notice how the price displays immediately without server call.
Here is when data-* support started for each browser:
 Chrome
|
1.0 | Sep 2008 |
 Firefox
|
1.0 | Sep 2002 |
 IE/Edge
|
1.0 | Aug 1995 |
 Opera
|
1.0 | Jan 2006 |
 Safari
|
1.0 | Jan 2003 |
Back to <optgroup>
